BF2S Forums Tunisian president flees country.

Tunisian President Zine El Abidine Ben Ali quit on Friday after 23 years in power and fled the north African state as the authorities declared a state of emergency following deadly protests.

Prime Minister Mohammed Ghannouchi announced on state television that he had taken over as interim president, after a day of violent clashes between rock-throwing protesters and riot police in the streets of central Tunis.

"I call on Tunisians of all political persuasions and from all regions to demonstrate patriotism and unity," Ghannouchi said in a solemn live address.

Government sources told AFP that Ben Ali had left the country but it was not immediately clear where he was headed.

Ben Ali had promised on Thursday to stand down at the end of his mandate in 2014 and said the prices of basic foodstuffs would be cut.

Ghannouchi announced after another day of violence Friday that the government had been sacked and elections would be held in six months.

Ben Ali's dramatic departure came after several tumultuous weeks in which a protest over high food prices and unemployment in central Tunisia escalated and spread across the country, with anger against the president spilling into the streets.

"We just want democracy," 24-year-old Hosni, his face wrapped in a Tunisian flag against tear gas, said during riots ahead of the president's departure.

Tarek, 19, an engineering student with a rock in one hand and a metal bar in the other, said: "Our president has promised a lot. They're empty promises."

Protesters even descended on the interior ministry in Tunis, one of the symbols of 74-year-old Ben Ali's iron-fisted rule, where they openly chanted for his swift departure and paid tribute to the "blood of the martyrs".

"I've never seen anything like this. This is our chance. We'll never have another chance like this," said Adel Ouni, a 36-year-old diplomat, observing the protest, adding: "This is a social revolution."

Tunisian authorities then declared a national state of emergency, banning public gatherings and imposing a strict curfew across the country.

"The police and the army are authorised to fire on any suspect person who has not obeyed orders or fled without the possibility of being stopped," said a government statement carried by the official TAP news agency.

The army meanwhile took control of the main international Tunis Carthage airport and airspace was shut down, an airport source said.

In earlier comments on TAP, Ghannouchi said the president had decided "to dismiss the government and call early elections in six months".

The statement said the decision had been made the day before, but there had been no mention of the government's dismissal in Ben Ali's national address Thursday although he did take a swipe at his lieutenants for "deceit".

But the apparent concessions did little to stem the calls for change with the chant of "Ben Ali Out!" echoing at demonstrations across the country.

"This is a demonstration of hope," Moncef Ben Mrad, editor of an independent newspaper, said at the protest in Tunis earlier on Friday.

"It is the birth of a people who demand more freedom and that the families that have looted the country return the wealth and are called to account."

Speaking at a news conference in Paris, Tunisia's main opposition parties, both legal and banned, had demanded Ben Ali step down in favour.

According to a Paris-based rights group, 66 people have been killed since mid-December in the worst unrest faced in Ben Ali's rule, about three times higher than the official toll.

Although Ben Ali had called on Thursday for an end to live firing by his security forces, medical sources said 13 people had been shot dead on the same night in the Tunisian capital and suburbs.

In a bid to quell the unrest, the president had promised in his national address that he would not seek another term in office and vowed to liberalise the political system.

Addressing other complaints, he also pledged to lower the prices of basic commodities such as milk, bread and sugar, and lift restrictions on the Internet.

With the tensions mounting, the leading tour operator Thomas Cook said it was evacuating more than 4,000 holidaymakers from the Mediterranean nation including from Germany, Britain and Ireland.

France became the latest in a list of European countries to advise its citizens against travel to Tunisia.